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| Author | Vermeiren, V.; Bogaerts, A. | ||||
| Title | Supersonic Microwave Plasma: Potential and Limitations for Energy-Efficient CO2Conversion | Type | A1 Journal Article | ||
| Year | 2018 | Publication | Journal Of Physical Chemistry C | Abbreviated Journal | J Phys Chem C |
| Volume | 122 | Issue | 45 | Pages | 25869-25881 |
| Keywords | A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
| Abstract | Supersonic flows provide a high thermodynamic nonequilibrium, which is crucial for energy-efficient conversion of CO 2 in microwave plasmas and are therefore of great interest. However, the effect of the flow on the chemical reactions is poorly understood. In this work, we present a combined flow and plasma chemical kinetics model of a microwave CO 2 plasma in a Laval nozzle setup. The effects of the flow field on the different dissociation and recombination mechanisms, the vibrational distribution, and the vibrational transfer mechanism are discussed. In addition, the effect of experimental parameters, like position of power deposition, outlet pressure, and specific energy input, on the CO 2 conversion and energy efficiency is examined. The short residence time of the gas in the plasma region, the shockwave, and the maximum critical heat, and thus power, that can be added to the flow to avoid thermal choking are the main obstacles to reaching high energy efficiencies. |
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000451101400016 | Publication Date | 2018-11-15 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1932-7447 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 4.536 | Times cited | 5 | Open Access | Not_Open_Access |
| Notes | Fonds Wetenschappelijk Onderzoek, G.0383.16N ; | Approved | Most recent IF: 4.536 | ||
| Call Number | PLASMANT @ plasmant @c:irua:155412 | Serial | 5070 | ||
| Permanent link to this record | |||||
| Author | Van Alphen, S.; Vermeiren, V.; Butterworth, T.; van den Bekerom, D.C.M.; van Rooij, G.J.; Bogaerts, A. | ||||
| Title | Power Pulsing To Maximize Vibrational Excitation Efficiency in N2Microwave Plasma: A Combined Experimental and Computational Study | Type | A1 Journal article | ||
| Year | 2020 | Publication | Journal Of Physical Chemistry C | Abbreviated Journal | J Phys Chem C |
| Volume | 124 | Issue | 3 | Pages | 1765-1779 |
| Keywords | A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract | Plasma is gaining increasing interest for N2 fixation, being a flexible, electricity-driven alternative for the current conventional fossil fuel-based N2 fixation processes. As the vibrational-induced dissociation of N2 is found to be an energy-efficient pathway to acquire atomic N for the fixation processes, plasmas that are in vibrational nonequilibrium seem promising for this application. However, an important challenge in using nonequilibrium plasmas lies in preventing vibrational−translational (VT) relaxation processes, in which vibrational energy crucial for N2 dissociation is lost to gas heating. We present here both experimental and modeling results for the vibrational and gas temperature in a microsecond-pulsed microwave (MW) N2 plasma, showing how power pulsing can suppress this unfavorable VT relaxation and achieve a maximal vibrational nonequilibrium. By means of our kinetic model, we demonstrate that pulsed plasmas take advantage of the long time scale on which VT processes occur, yielding a very pronounced nonequilibrium over the whole N2 vibrational ladder. Additionally, the effect of pulse parameters like the pulse frequency and pulse width are investigated, demonstrating that the advantage of pulsing to inhibit VT relaxation diminishes for high pulse frequencies (around 7000 kHz) and long power pulses (above 400 μs). Nevertheless, all regimes studied here demonstrate a clear vibrational nonequilibrium while only requiring a limited power-on time, and thus, we may conclude that a pulsed plasma seems very interesting for energyefficient vibrational excitation. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000509438600001 | Publication Date | 2020-01-23 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1932-7447 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.7 | Times cited | Open Access | ||
| Notes | Fonds Wetenschappelijk Onderzoek, 30505023 GoF9618n ; This research was supported by the Excellence of Science FWO-FNRS project (FWO Grant ID GoF9618n, EOS ID 30505023). The calculations were performed using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UAntwerpen), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the UAntwerpen. | Approved | Most recent IF: 3.7; 2020 IF: 4.536 | ||
| Call Number | PLASMANT @ plasmant @c:irua:165586 | Serial | 5443 | ||
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| Author | Choukroun, D.; Daems, N.; Kenis, T.; Van Everbroeck, T.; Hereijgers, J.; Altantzis, T.; Bals, S.; Cool, P.; Breugelmans, T. | ||||
| Title | Bifunctional nickel-nitrogen-doped-carbon-supported copper electrocatalyst for CO2 reduction | Type | A1 Journal article | ||
| Year | 2020 | Publication | Journal Of Physical Chemistry C | Abbreviated Journal | J Phys Chem C |
| Volume | 124 | Issue | 124 | Pages | 1369-1381 |
| Keywords | A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA); Applied Electrochemistry & Catalysis (ELCAT) | ||||
| Abstract | Bifunctionality is a key feature of many industrial catalysts, supported metal clusters and particles in particular, and the development of such catalysts for the CO2 reduction reaction (CO2RR) to hydrocarbons and alcohols is gaining traction in light of recent advancements in the field. Carbon-supported Cu nanoparticles are suitable candidates for integration in the state-of-the-art reaction interfaces, and here, we propose, synthesize, and evaluate a bifunctional Ni–N-doped-C-supported Cu electrocatalyst, in which the support possesses active sites for selective CO2 conversion to CO and Cu nanoparticles catalyze either the direct CO2 or CO reduction to hydrocarbons. In this work, we introduce the scientific rationale behind the concept, its applicability, and the challenges with regard to the catalyst. From the practical aspect, the deposition of Cu nanoparticles onto carbon black and Ni–N–C supports via an ammonia-driven deposition precipitation method is reported and explored in more detail using X-ray diffraction, thermogravimetric analysis, and hydrogen temperature-programmed reduction. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and energy-dispersive X-ray spectroscopy (EDXS) give further evidence of the presence of Cu-containing nanoparticles on the Ni–N–C supports while revealing an additional relationship between the nanoparticle’s composition and the electrode’s electrocatalytic performance. Compared to the benchmark carbon black-supported Cu catalysts, Ni–N–C-supported Cu delivers up to a 2-fold increase in the partial C2H4 current density at −1.05 VRHE (C1/C2 = 0.67) and a concomitant 10-fold increase of the CO partial current density. The enhanced ethylene production metrics, obtained by virtue of the higher intrinsic activity of the Ni–N–C support, point out toward a synergistic action between the two catalytic functionalities. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000508467700015 | Publication Date | 2020-01-07 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1932-7447; 1932-7455 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.7 | Times cited | 24 | Open Access | OpenAccess |
| Notes | ; N.D. acknowledges sponsoring from the research foundation of Flanders (FWO) in the frame of a postdoctoral grant (12Y3919N N.D.). J.H. greatly acknowledges the Research Foundation Flanders (FWO) for support through a postdoctoral fellowship (28761). T.V.E. and P.C. acknowledge financial support from the EU-Partial-PGMs project (H2020NMP-686086). The authors also acknowledge financial support from the university research fund (BOF-GOA PS ID No. 33928). ; | Approved | Most recent IF: 3.7; 2020 IF: 4.536 | ||
| Call Number | UA @ admin @ c:irua:165326 | Serial | 6286 | ||
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